An electronic product, such as a notebook computer, is usually provided on a main unit thereof with one or more universal serial bus (USB) sockets, to which different peripherals are electrically connected for use, and one or two memory-card sockets, in which a memory card may be plugged to allow access of data stored in the memory card.
In practical use, the memory-card sockets are not so frequently used as the USB-sockets. Therefore, there are times the USB sockets on the notebook computer are not sufficient for use while there are still unused memory-card sockets.
To fully utilize the memory-card sockets, attempts have been made to provide a memory-card socket that serves as a connecting port not only for connecting general memory cards, but also different peripherals to a computer. For this purpose, the peripheral may include a memory-card shaped plug connector. The peripheral including a memory-card shaped plug connector is referred to as a memory-card type peripheral. Examples of the memory-card type peripherals include memory-card type digital camera, memory-card type network transmission equipment, etc. By plugging the memory-card shaped plug connector in a memory-card socket on a computer, the memory-card type peripheral may be used with the computer.
However, the currently commercially available memory cards have various configurations and specifications, such as SECURE DIGITAL (SD card) 11, as shown in FIG. 1; MEMORY STICK (SD card) 12, as shown in FIG. 2; and COMPACT FLASH (CF card) 13, as shown in FIG. 3. Memory cards of different configurations require different memory-card sockets that are not compatible with one another. Since it is unknown into what type of memory-card socket a finished product of the memory-card type peripheral would be plugged, it is necessary to produce in advance a large number of peripherals with differently configured memory-card plug connector for customers' choice. For example, peripherals for the same purpose have to be produced in three categories, namely, peripherals with SD-card plug connector 21, as shown in FIG. 4, peripherals with MS-card plug connector 22, as shown in FIG. 5, and peripherals with CF-card plug connector 23, as shown in FIG. 6. This would inevitably largely increase the manufacturing cost of the memory-card type peripherals and lower the adaptability of the produced peripherals. A user has to pay more money to buy memory-card type peripherals with different memory-card shaped plug connectors to work with different types of memory-card sockets on the computer.